Although the present invention will be described with particular reference to the use of glycine betaine as one example of the osmolyte regulator administered to cherry plants to control stress in the plants, particularly the tendency of the skins of the cherries to crack, it is to be noted that the scope of the present invention is not restricted to the described embodiment but rather the present invention is more extensive so as to include the use of other osmolyte regulators, to other ways of administering the regulators, and to other uses of the chemical compounds than as osmolyte regulators, and to the use of the regulators on crops other than those specifically described, particularly on pears, peaches and the like.
Cherries are a crop having considerable economic value. As cherries grow they are often subjected to stress in one or more forms. The cherries respond to stress by cracking their skins. Consequently, the development of stress within the cherries is easily and readily observable and demonstrable. The amount of cracking developed by the cherries is an indication of the amount of stress to which the cherries are being subjected. The main causes of skin cracking include too much or too little water, inadequate nutrition, low light intensity, low temperatures, and the like.
Cracks usually develop in cherries during the latter stages of ripening of the cherries and cracking is more severe under wetter conditions than under drier conditions. It is believed that cracking is caused by a build up of pressure within the fruit so that the skin is not strong enough to withstand the increase in pressure without splitting.
The development of cracks in the skin of ripe cherries reduces the economic worth of the crop since cherries with cracked skins cannot be sold at a premium price as high quality table fruit, but rather can only be used in lower quality applications, such as for example in making jams and the like, which lower quality applications do not produce the same economic returns to the growers as when the cherries are sold as high quality table fruit. Additionally owing to the cracking of the skins secondary infection such as for example by moulds, brown rot, fungi and other pathogens can infect and develop within the cherries, so that a majority of cracked fruit is often not suitable for any purpose and is simply dumped. Therefore, any reduction in the amount or extent of cracking in cherries will be beneficial to the grower as the fruit will be of a more uniform high quality and demand higher prices when sold, which increases the economic value of the crop and the monetary return to the grower.
The same applies to many other types of fruit such as for example, pears, peaches and the like.
Therefore, it is an aim of the present invention to provide a method of administering an osmolyte regulator to a plant, particularly to cherry plants for controlling the stress induced or developed in the growing plant so as to overcome or at least reduce the tendency of the skins of the plant to crack, particularly during ripening.